This invention relates generally to the smoking of comestible products to impart a desirable smokey flavor and color to the products and, more particularly, to a method for producing a refined smoke vapor for imparting improved smokey flavor and color to comestible products, to a smoking method employing the refined vapor and to comestible products smoked with that refined vapor. It also relates to a method for producing a refined liquid smoke condensate, to the application of that condensate to comestible products and to comestible products produced thereby.
The smoking of comestible products, including meat, fish and cheese, by suspending the products in an enclosure through which smoke generated by the partial combustion of certain hardwoods is passed is one of the oldest forms of food preservation. It produces a product with smokey flavor and color characteristics desired by a large segment of the world population. Unfortunately, there are drawbacks to this traditional direct smoking method.
Smoking comestible products directly with the smoke of burning hardwood requires that large quantities of hardwood chips or sawdust first be transported to the smoking site for burning and then that the large quantities of burnt residues which remain be disposed of. The concentration and density of the smoke is difficult to control in direct smoking so that there is significant variation in the flavor and color in the smoked comestible product between application runs. Finally, the direct generation of wood smoke produces copious amounts of tars, combustible flyash and carcinogens which are necessarily introduced into the comestible products.
Notwhstanding these significant drawbacks, the traditional direct smoking process has one very important advantage. The smoke produced by smoldering wood in the direct smoking process is in a form which evenly distributes itself within the smoking chamber to uniformly flavor and color the comestible products being smoked.
A relatively recent improvement in the traditional smoking process has been the development of aqueous wood smoke flavored solutions known as "liquid smoke" which are manufactured at a single large facility from the smoke produced by wood combustion and then distributed for on-site application in liquid form. Techniques for manufacturing liquid smoke are described, for example, in U.S. Pat. No. 3,873,741 and 3,106,473.
The advantages of the use of liquid smoke in lieu of direct smoking are myriad. On-site handling of sawdust, wood chips and ash is eliminated. Flyash and known carcinogens are removed from the liquid smoke. An increased level of control of smokey flavor and color may be achieved.
Liquid smoke may be applied by directly adding the liquid to processed comestible products during processing, by immersing the products in the liquid, by spraying or coating the liquid directly onto the comestible products or by producing a liquid smoke mist and then suspending the comestible product in the mist. Although the misting technique is presently the most widely used, it has a number of serious drawbacks.
First, liquid smoke contains tars which clog spray nozzles and adhere to smoking enclosure surfaces requiring constant monitoring of nozzle air supply pressures and significant downtime for unclogging of nozzles and cleaning of smoke enclosure surfaces. Secondly, it is difficult to keep the mist suspended and evenly distributed throughout the enclosure. As a result, the levels of smokey flavor and color imparted to the comestible products suspended in the enclosure are often uneven. Furthermore, fans which are required to circulate air through the enclosure must be turned off when the mist is introduced to prevent further unevenness in mist distribution, extending the processing times.
Given the significant advantages inherent in the use of liquid smoke generally, various techniques have been proposed to "regenerate" liquid smoke into a gaseous or vapor form having the advantages inherent in traditional direct smoking. Proposed liquid smoke vapor regeneration techniques have generally involved heating the liquid smoke to completely volatiize it and then applying the resulting vapor, as in the direct smoking process.
While theoretically highly desirable, in fact, prior vapor regeneration techniques have not found commercial acceptance because of the burning of the liquid smoke during the regeneration process which produces an undesirable burned flavor in the resulting product, as well as the build-up of tars on heating surfaces, which interferes with the volatilization process. These tars, it has been found, significantly interfere with heat transfer and, while hot, tend to take fire, producing localized tar fires on the heating surfaces and in duct which conduct the regenerated vapor to the smoking enclosure. In addition, the liquid smoke regeneration techniques heretofore describd have not provided a practical way of tailoring the flavor and color achieved in the smoking process.
It is therefore an object of the present invention to provide an improved liquid smoke vapor regeneration technique.
It is another object of the present invention to provide a method for producing, from conventional liquid smoke, a refined liquid smoke vapor and a refined liquid smoke condensate for imparting enhanced smokey flavor and color to comestible products.
It is yet another object of the present invention to provide a liquid smoke regeneration method in which tar build-up on heating surfaces and ducts is reduced or eliminated.
It is a further object of the present invention to provide a comestible product with enhanced smokey flavor and color.
These and other objects of the present invention will become apparent to those skilled in the art upon consideration of the accompanying specification, claims and drawings.